Ablation treatment is known as prevalent technology of non pharmacological treatment to the affected area. However, in this treatment, because the treated area is ablated using electrode, it is difficult to treat the deep portion of the arrhythmia of tachyarrhythmia and it has a problem that the serious thrombus obstruction may occurred in combination with the tachyarrhythmia due to the heat generated by the electrode.
Further, the extracorporeal shock wave lithotripsy (ESWL) to crush and remove the stone in the ureter or kidney by instantaneously forming high pressured area in limited space, in which the high pressured area is formed by converging the underwater shockwave generated by irradiating the pulse laser beam underwater, is established.
The applicant has succeeded in providing the small underwater shockwave generating device incorporating above underwater shockwave converging method, which can be employed in the catheter, like shown in patent document 1.
Further, it is known that the strong shockwave can be generated by using the optical fiber having a rough surface rather than using the optical fiber having a mirror surface, like shown in paragraph 3.6 of non patent document 1.